Methods of satellite pointing using a synchronization signal based on a modulated pseudo random sequence are known in the prior art. This modulation can for example be carried out by using a two-state phase modulation (also known by the name of BPSK for Binary Phase Shift Keying). This synchronization signal, emitted in one or more temporal intervals, is also known in the prior art by the name of beacon.
However, as low-cost satellite terminals generally comprise a low-performance local oscillator, the terminals generally exhibit a frequency shift with the satellite or the terrestrial station of several kHz, to which is added a possible shift caused by the Doppler effect.
These shifts in frequency slow down the synchronization between the satellite terminal and the satellite or the terrestrial station. Indeed, the terminal is required to make several assumptions about this possible shift in frequency. The time required for the synchronization will therefore depend on the computation power available in the satellite terminal and on the number of assumptions to be made. For example if the receiver must search for the synchronization signal in a span of 50 kHz in increments of 1 kHz, then the satellite terminal is required to make 101 assumptions about the shift in frequency. If each assumption requires a computation of 10 seconds, the total synchronization time is around 17 minutes. Moreover the computation power, required for a first synchronization, is in general greater than the computation power required for tracking this synchronization. The computation power used for the process of initial synchronization is therefore under-used during the major part of the time.